Rabbit Terrine with Green Olives and Pistachios

Name: Rabbit Terrine with Green Olives and Pistachios
Ingredients: 1 (3-lb) rabbit, cut into 8 pieces; 4 shallots, thinly sliced; 2 carrots, thinly sliced; 3 fresh parsley sprigs; 2 fresh thyme sprigs; 1 leek (green part only), rinsed; 1 head garlic, left unpeeled and halved horizontally; 1/2 teaspoon black peppercorns, cracked; 1/2 teaspoon salt; 6 1/4 cups cold water; 2 large egg whites plus shells, crushed; 4 teaspoons unflavored gelatin (from two 1/4-oz envelopes); 1 tablespoons Madeira; 1/2 teaspoon fennel seeds, toasted*; 1/2 cup picholine or other brine-cured green olives (3 oz), pitted and coarsely chopped; 1/3 cup salted shelled pistachios, coarsely chopped; 3 tablespoons thinly sliced fresh chives; 1 teaspoon chopped fresh thyme; 3/4 teaspoon black pepper; Accompaniment: 18 very thin slices firm white sandwich bread, each slice buttered and cut into 2 pieces the shape of terrine slices, then toasted.**; 2 (12- by 2-inch) tapered narrow rectangular terrines; kitchen string; 2 (11 1/2- by 1 1/2-inch) strips of corrugated cardboard wrapped well with foil; 2 (10- to 11-inch) rolling pins or high-shouldered wine bottles